#include <bits/stdc++.h>
using namespace std;

int n;
double cnt = 0;

int main() {
    cin >> n;
    double age;
    for (int i = 1; i <= n; i++) {
        cin >> age;
        cnt += age;
    }
    cout << fixed << setprecision(4) << cnt / n;
    return 0;
}